High temperature protected wire bonded sensors

ABSTRACT

Systems and methods are disclosed for packaging sensors for use in high temperature environments. In one example implementation, a sensor device includes a header; one or more feedthrough pins extending through the header; and a sensor chip disposed on a support portion of the header. The sensor chip includes one or more contact pads. The sensor device further includes one or more wire bonded interconnections in electrical communication with the respective one or more contact pads and the respective one or more feedthrough pins. The sensor device includes a first sealed enclosure formed by at least a portion of the header. The first sealed enclosure is configured for enclosing and protecting at last the one or more wire bonded interconnections and the one or more contact pads from an external environment.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation claiming priority under 35 U.S.C. §120 to U.S. patent application Ser. No. 16/552,172, filed 27 Aug. 2019,and published as U.S. Patent Publication US20200011757 on 9 Jan. 2020.U.S. patent application Ser. No. 16/552,172 is a continuation of U.S.patent application Ser. No. 15/667,117, filed 2 Aug. 2017, and publishedas U.S. Patent Application Publication No. US20190041288 on 7 Feb. 2019,the contents of which are incorporated herein by reference as if fullyset forth.

FIELD

The disclosed technology relates to electronic device packaging andelectrical interconnections suitable for high temperature operability,and in particular, to package construction and techniques for protectionof wire bonded sensors.

BACKGROUND

Some of the most challenging aspects associated with producing reliablesensors suitable for use in harsh, high temperature environments includeproviding appropriate packaging for housing the sensing element andselecting materials for the electrical interconnections among thesensing element and the selected package.

Various approaches have been proposed for packaging piezoresistivepressure sensors, including the utilization of a leadless semiconductorsensor chip having contacts disposed on the surface of the chip, andconfigured to accept pins for electrical communication, as described inU.S. Pat. No. 5,955,771 to Kurtz, et al., and assigned to KuliteSemiconductor Products, Inc., the Assignee of this application, thecontents of which are incorporated herein by reference. The leadlesssensor chip approach relies on achieving excellent thermal expansionmatch of all of the components used, while making electricalinterconnections using conductive glass/metal mixture.

As sensing elements are needed for use in even more extremeenvironments, including higher-pressure and/or higher temperatureapplications, there is a need for specific sensor designs withassociated packaging and interconnections, such as described in U.S.Pat. No. 5,614,678 to Kurtz, et al., and assigned to KuliteSemiconductor Products, Inc., the Assignee of this application, thecontents of which are incorporated herein by reference.

The leadless sensor approach may be appropriate in certain sensingapplications; however, it would be beneficial to utilize mature wirebonding technology for metallic interconnections. Wire bondingtechnology has long been considered inadequate for high temperaturesensor use due to reliability issues when exposed to high temperature incorrosive and/or oxidizing media.

A need exists for systems and methods in which a transducer chip can besecured within a housing and electrically connected using wire bonding,with the associated interconnections capable of reliable operation atelevated temperatures and/or extreme environments.

BRIEF SUMMARY

Certain example implementations of the disclosed technology may includesystems and methods for packaging sensors for reliable operation in hightemperature environments. In one example implementation, a sensor deviceis provided. The sensor device includes a header; one or morefeedthrough pins extending through the header; and a sensor chipdisposed on a support portion of the header. The sensor chip includesone or more contact pads. The sensor device further includes one or morewire bonded interconnections in electrical communication with therespective one or more contact pads, and the one or more wire bondedinterconnections are further in electrical communication with therespective one or more feedthrough pins. The sensor device includes afirst sealed enclosure formed by at least a portion of the header. Thefirst sealed enclosure is configured to isolate at least the one or morewire bonded interconnections and the one or more contact pads from anexternal environment. The sensor device is configured for increasedreliability when used in high temperature environments.

In another example implementation, a method is provided. The method caninclude sealing a sensor chip to a support portion of a header, whereinthe sensor chip includes one or more sensor contact pads, and the headerincludes one or more bores extending through the header. The methodincludes attaching one or more electrical isolators to the supportportion of the header; disposing one or more feedthrough pin contactpads on the respective one or more electrical isolators; attaching afirst end of one or more wire bonded interconnections to the respectiveone or more sensor contact pads; attaching a second end of the one ormore wire bonded interconnections to the respective one or morefeedthrough pin contact pads; installing one or more feedthrough pinsthrough the respective one or more bores such that the one or morefeedthrough pins are in electrical communication with the respective oneor more feedthrough pin contact pads; and forming a first sealedenclosure to enclose and protect one or more of the wire bondedinterconnections, the one or more sensor contact pads, the one or morefeedthrough pin contact pads, the one or more feedthrough pins, and atleast the first portion of the sensor chip.

Other implementations, features, and aspects of the disclosed technologyare described in detail herein and are considered a part of the claimeddisclosed technology. Other implementations, features, and aspects canbe understood with reference to the following detailed description,accompanying drawings, and claims.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 depicts a cross-sectional side view of a sensor device 100structure including a sensor chip 108 with (externally) exposed sensorchip portions 102, according to an example implementation of thedisclosed technology.

FIG. 2 depicts an example top view layout of the sensor chip 108,according to an example implementation of the disclosed technology.

FIG. 3 depicts another example embodiment of a sensor device 200structure, according to an example implementation of the disclosedtechnology.

FIG. 4 depicts another example embodiment of a sensor device 300structure, according to an example implementation of the disclosedtechnology.

FIG. 5 depicts another example embodiment of a sensor device 400structure, including a sensor chip 408, according to an exampleimplementation of the disclosed technology.

FIG. 6 depicts an example top view layout of the sensor chip 408,according to an example implementation of the disclosed technology.

FIG. 7 depicts another example embodiment of a sensor device 500structure having a sensor chip 508 with a different layout as comparedwith the previous example embodiments.

FIG. 8 depicts a top view layout of a sensor chip 508, as described withrespect to the sensor device shown in FIG. 7.

FIG. 9 depicts another example sensor device 600 structure configuredwith a protective outer diaphragm 606 for providing a sealed sensor chipenvironment 608, according to an example implementation of the disclosedtechnology.

FIG. 10 depicts another example sensor device 700 structure configuredwith a protective outer diaphragm 606 for providing a sealed sensor chipenvironment 608, according to an example implementation of the disclosedtechnology.

FIG. 11 depicts another sensor device 800 structure having a sealedenvironment 812, and with a sensor chip 808 disposed directly on aportion of the base of the header 104, according to an exampleimplementation of the disclosed technology.

FIG. 12 shows a top-view layout of a high temperature sensor chip 808,according to an example implementation of the disclosed technology.

FIG. 13 is a flow diagram of a method 900, according to an exampleimplementation of the disclosed technology.

DETAILED DESCRIPTION

Certain example implementations of the disclosed technology includedevices and techniques for providing electronic device packaging andinterconnections suitable for high temperature operability.

The terms “interconnection,” “interconnect,” “connection,” “junction,”etc., as used herein, may refer to a physical and/or electricalconnection between or among two or more components and/or materials,including but not limited to conductors, semiconductors, insulators,contact pads, wires, barrier layers, oxides, etc.

The disclosed technology includes systems and methods for making andutilizing sensors with packaging having internal electricalinterconnections that are produced by wire bonding. Certain exampleimplementations include sensor package design and construction thatprovides an inert environment for the sensing element, the wire bondedinterconnects, and the associated contact pads. The example embodimentsdisclosed herein may enable a variety of sensor chip designs to bepackaged for specific measurements in various applications, including,but not limited to high temperature environments and/or corrosiveenvironments. In accordance with an example implementation of thedisclosed technology, the sealing of the wire bonds within the inertpackaging environment may enable the device to operate in conductivemedia, and may reduce or eliminate the effects of corrosion on themetallic interface(s). Furthermore, certain example implementation ofthe disclosed technology may greatly slow down interdiffusion of metals,thus allowing the barrier metals to survive at higher temperatures (forexample, above 600° C.) for longer periods of time.

Several embodiment variations of the disclosed technology are describedherein with reference to the accompanying figures. FIGS. 1-12 depictexample transducers and related packaging structures, according tocertain example implementations of the disclosed technology. A generaloverview of the disclosed technology and associated example embodimentsmay be best understood by reviewing groups of the attached figures. Forexample, FIGS. 1-8 illustrate wire bonded sensors, sensor chip patternlayouts, and associated packaging with all of the metal contacts andelectrical interconnections contained within a sealed inert environment106, but with portions or regions of the sensor chip exposed to themeasurement environment. For example, in FIGS. 1-8, the exposed sensorchip portions 102 (i.e., regions exposed to the measurement environment)do not include contacts or electrically active or electricallyfunctional components. Such transducers are functional at hightemperatures (for example, above 600° C.) in any measurementenvironments that are not corrosive or are not significantly ordestructively chemically reactive with the transducer header 104 and/orwith the exposed sensor chip regions 102.

FIGS. 9 and 10 depict certain example high temperature transducerembodiments 600, 700 in which all metal contacts and all electricalinterconnections are contained in a first sealed inert environment 106,and all the remaining portions of the sensor chip (not contained in thefirst sealed inert environment 106) are contained in a second sealedinert environment 608.

FIGS. 11 and 12 depict another example implementation of a hightemperature transducer 800 and corresponding sensor chip 808 with allmetal contacts, all electrical interconnections, and the entire sensorchip 808 contained in the same sealed inert environment 812. Asdisclosed herein, and by virtue of the sealed environments 106, 608,812, the transducers depicted in FIGS. 9-11 may be functional andsuitable for use at high temperatures (above 600° C.) in measurementenvironments that are not corrosive or that are not significantly ordestructively chemically reactive with the transducer header 104, butthat could be corrosive or significantly or destructively chemicallyreactive with the associated sensor chip 108, 408, 808. Some ofadditional details of the example embodiments will now be discussed withreference to FIGS. 1-13.

Certain example implementations described herein may be utilized toaddress the need for enhancing the reliability of sensor devices,particularly for use in high temperature and/or corrosive environments.Certain example implementations provide one or more protectiveenclosures to isolate wire bonds, contact pads, and/or sensor chips froman external environment. Furthermore, in certain exampleimplementations, the enclosure(s) may include an inert environment tofurther prevent or reduce degradation of the associated enclosedinternal components.

FIG. 1 depicts a cross-sectional side view of a sensor device 100structure including a sensor chip 108 with (externally) exposed sensorchip portions 102. In this example implementation, the sensor chip 108substrate may be supported by support portions 105 of the header 104. Inan example implementation, a seal 118, such as glass (or other hightemperature sealing or chip mounting material) may be utilized betweenthe bottom of the chip substrate and the support portion 105 of theheader 104. As depicted in this example embodiment, the sensor chip 108substrate may include vias that allow access to the sensor chip contactpads 112, and that allow wire bonds or other electrical interconnections110 to pass through the vias for connection to the feedthrough pins 116.Upon assembly of the sensor device 100 package, the vias may form partof the sealed interconnect environment 106 for protection of theinternal portion of the sensor chip 108, the electrical interconnections110, the sensor chip contact pads 112, the pin contact pads 114, thefeedthrough pins 116, etc. In accordance with an example implementationof the disclosed technology, the header 104 may include various upperand lower sections that may be joined with a header weld 122 to furtherseal the sensor device 100, for example, after the internal connectionsare made and after the appropriate internal assembly is completed.

The example electrical interconnection 110 shown in FIG. 1 may beutilized for electrically connecting the sensor chip contact pads 112 topin contact pads 114 that may be in communication with the feedthroughpins 116. The feedthrough pins 116 may be fed through the bottom portionof the header 104 and sealed to the header 104. In this exampleimplementation, the use of wire bonding is depicted for the electricalinterconnection 110, however, certain implementations may utilizewelding, or other appropriate techniques for joining metal wires to thesensor chip contact pads 112, and to corresponding pin contact pads 114.

In accordance with an example implementation of the disclosedtechnology, the electrical interconnections 110 and pin contact pads 114may be isolated from the header 104 and/or from the support portions ofthe header 105 by high temperature electrical isolators 120. In anexample implementation, the pin contact pads 114 may be physicallysecured to a support portion 105 of the header 104, but electricallyisolated/separated from the header material by the high temperatureelectrical isolator 120. In an example implementation of the disclosedtechnology, the electrical isolator 120 may be utilized as needed toprevent unwanted electrical contact or communication between theelectrical interconnection components and certain portions of the sensordevice 100 packaging.

FIG. 1 also depicts an example embodiment that may utilize feedthroughpin inserts 126 for accepting the feedthrough pins 116. In certainexample implementations, the pin feedthrough inserts 126 may provideadvantages for assembling and sealing the space between the pins/insertsand the walls of the associated feedthrough apertures in the housing104. In an example implementation, a weld 124 or braze joint may beutilized to seal the pin 116 to the insert 126. In certain exampleimplementations, the feedthrough pins 116 and the feedthrough inserts126 may be made of metal. In an example implementation, the feedthroughinserts 126 may include a closed end 128, for example, to provideadditional sealing and to prevent leakage in/out of the sealedinterconnect environment 106. According to an example implementation ofthe disclosed technology, the space between the pins 116 and/or inserts126 and the walls of the associated feedthrough apertures in the housing104 may be sealed with an electrically isolating seal 130, such asglass.

In accordance with an example implementation of the disclosedtechnology, the sensor chip 108 may be sealed to and/or mounted on asupport portion 105 of the header 104 using a seal 118 such as glass orother appropriate sealing or mounting material using a technique similarwith that described in U.S. Pat. No. 5,955,771. For example, and asdiscussed above, the support portion 105 of the header 104 that supportsthe sensor chip 108 may also have installed high temperature electricalisolators 120 for providing electrical isolation between the electricalinterconnections 110 and the header components 104, 105. These hightemperature electrical isolators 120 may be made from ceramic, glass, orglass-ceramic type materials. In certain example implementations, someof these high temperature electrical isolators 120 may have metalcontacts with metal pins attached to these metal contacts. In an exampleimplementation, the metal pins can be made from one or more of: Kovar,stainless steel, Inconel, nickel, tungsten, molybdenum, platinum, orfrom other high temperature metal or metal alloy. In certain exampleimplementations, the metal pins may have a plated or deposited metallayer of gold, platinum, or other suitable metal or metal alloy.

As discussed above with FIG. 1, the feedthrough inserts 126, which mayinclude metal tubes, or other sealed electrical feedthroughs, may beinstalled within bores or apertures in the header 104 with hightemperature electrically isolating seals 130 for providing electricalisolation between the electrical interconnections 110 and the header104. In certain example implementations, the metal tube feedthroughinserts 126 can be made from one or more of: Kovar, stainless steel,Inconel, nickel, tungsten, molybdenum, platinum, or from other hightemperature metal or metal alloy, and could have a plated or depositedmetal layer of gold or platinum, or other suitable metal or metal alloy.

In accordance with certain example implementations of the disclosedtechnology, the header 104 and/or the support portion of the header 105may be made from one or more of: Kovar, stainless steel, Inconel,nickel, tungsten, molybdenum, platinum, or from other suitable hightemperature metal or metal alloy, and could have a plated or depositedmetal layer of gold or platinum, or of other suitable metal or metalalloy.

In accordance with an example implementation of the disclosedtechnology, the metal feedthrough inserts 126 can be sealed into header104, and at the same time can be electrically isolated from the headerusing a electrically isolating seal 130 that may include one or more of:glass, glass-ceramic, or other high temperature sealing and electricallyisolating materials.

According to an example implementation of the disclosed technology,electrical interconnections 110 may be made between the sensor chipcontact pads 112 and the corresponding pin contact pads 114 located onthe high temperature electrical isolator 120 (which may be in contactwith the support portion of the header 105. According to an exampleimplementation of the disclosed technology, the electricalinterconnections 110 may be made between the sensor chip contact pads112 and the corresponding pin contact pads 114 by one or more of: wirebonding, welding, or other appropriate technique for joining metal wiresto contacts. According to an example implementation of the disclosedtechnology, the electrical interconnections 110 may include wires madeof one or more of: gold, platinum, aluminum, nickel, copper or othersuitable metal or metal alloy.

In accordance with an example implementation of the disclosedtechnology, the metal pins 116 may be attached to the pin contact pads114 and inserted into the metal feedthrough inserts 126, or into othersealed electrical feedthroughs and through the corresponding bores inthe bottom portion of the header 104. In an example implementation, themetal pins 116 attached to the pin contact pads 114 may be configuredwith dimensions that allow them to reach inside the portions of thefeedthrough inserts 126 (or other sealed electrical feedthroughs)protruding outside from the header 104.

In accordance with an example implementation of the disclosedtechnology, the upper and lower portions of the header 104 may be joinedand sealed (for example, with a header weld 122) in an inertenvironment, preferably by electron beam welding, or by brazing, orother appropriate joining technique. In one example implementation, theupper and lower portions of the header 104 may be joined before themetal pins 116 that are attached to the pin contacts 114 and are sealedinto feedthrough inserts 126. In another example implementation, theupper and lower portions of the header 104 may be joined at the sametime the metal pins 116 that are attached to the pin contacts 114 andare sealed into feedthrough inserts 126. In yet another exampleimplementation, the upper and lower portions of the header 104 may bejoined after the metal pins 116 are attached to the pin contacts 114 andare sealed into feedthrough inserts 126.

If the metal pins 116 are sealed into the feedthrough inserts 126 afterthe upper and lower header portions are joined and sealed together, thenthis last sealing and joining process may be done in an inertenvironment to ensure that all metal contacts and electricalinterconnections inside the sensor device 100 are contained in an inertenvironment.

In accordance with certain example implementations of the disclosedtechnology, certain manufacturing steps may be carried out in an inertenvironment, such as in a chamber flooded with an inert gas such asnitrogen, helium, or argon. In certain example embodiments, the inertenvironment may help eliminate the formation of oxides or other unwantedmaterials during the welding and/or sealing processes. In certainexample implementations, by sealing the various enclosures in the inertenvironment, corrosive or reactive gasses in the internal portion(s) ofthe sensor device may be reduced or eliminated. In this respect, thereliability and/or lifetime of the device may be enhanced or extended,particularly in high temperature use environments.

In certain example implementations an inert gas substantially devoid ofother materials may flow into a processing chamber, oven, or otherassembly cavity to displace oxygen. The presence of inert gas mayprovide an oxygen-free environment to shield the associated componentsof the sensor device parts, for example, to inhibit the formation ofoxides during the sealing process and/or to displace oxygen from theinternal enclosure of the sensor device before it is welded and/orsealed. In some implementations, the assembly and/or sealing of thesensor device in the inert environment may allow the formation of weldsor seals between component parts without the use of fluxes and/ormechanical scrubbing, while the inert gas-rich environment may furtherprevent the formation of additional oxides on the welds, seals, oradhesives.

According to an example implementation of the disclosed technology, andwith continued reference to FIG. 1, the metal feedthrough inserts 126(or other sealed electrical feedthroughs) may be manufactured with aclosed end 128 and may be sealed at the end protruding outside theheader 104. In this example configuration, the metal feedthrough inserts126 may be first crimped after inserting the metal pins 116 and welded,preferably by resistance welding, brazed, or permanently joinedmechanically and electrically by another appropriate metal joiningtechnique.

In an example implementation, the upper and lower header portions may bejoined (i.e., by the header weld 122) and sealed in an inertenvironment, preferably by electron beam welding, or by brazing, orother appropriate joining technique, before, at the same time, or afterthe metal pins 116 are joined to the feedthrough inserts 126 (or othersealed electrical feedthroughs) by welding, brazing, or otherappropriate joining technique.

FIG. 2 depicts an example top view layout of the sensor chip 108 (suchas the sensor chip 108 depicted in FIG. 1) having the sensor chipcontact pads 112 configured towards the periphery of the sensor chip108. In this example implementation, the sensor chip 108 may have asimilar structure as described in U.S. Pat. No. 5,955,771 (incorporatedherein by reference) and U.S. Pat. No. 8,656,784 to Ned, et al., andassigned to Kulite Semiconductor Products, Inc., the Assignee of thisapplication, the contents of which are incorporated herein by reference.

FIG. 3 depicts another example embodiment of a sensor device 200structure that may utilize a similar sensor chip 108 as previouslydiscussed with respect to FIGS. 1 and 2. In this example embodiment, thesensor chip 108 and part of the electrical interconnections 110 schememay be similar with that described in FIG. 1, with the difference beingthat the electrical isolators 120, pin contact pads 114, and associatedfeedthrough pins 116 may be located on the periphery of the sensordevice 200, as opposed to the layout shown in FIG. 1, in which theelectrical isolators 120, pin contact pads 114, and associatedfeedthrough pins 116 are located closer to the central vertical axis ofthe sensor device 100.

FIG. 4 depicts another example embodiment of a sensor device 300structure that may utilize a similar sensor chip 108 as previouslydiscussed with respect to FIGS. 1-3. In this example embodiment, thesensor chip 108 and part of the electrical interconnections 110 schememay be similar with that described in FIG. 3, with the difference beingthat the sensor chip 108 is supported only at the periphery of thesupport portion of the header 105, and without the central portion ofthe support portion of the header 105 being in the way. In the exampleembodiment, as shown in FIG. 4, the sealed interconnection environment106 may have significantly more open space (compared with theembodiments shown in FIGS. 1 and 3), which may provide certain assemblybenefits, for example for making the electrical interconnections 110between the sensor chip contact pads 112 and the corresponding pincontact pads 114.

FIG. 5 depicts another example embodiment of a sensor device 400structure that may utilize a sensor chip 408 having a slightly differentlayout compared to the sensor chip 108 previously described anddiscussed with respect to FIGS. 1-4. Similar to the embodiment as shownin FIG. 4, the sensor chip 408 is supported at the periphery of thesupport portion of the header 105, and without the presence of a centralportion of the support portion of the header 105. In the exampleembodiment, as shown in FIG. 5, the sealed interconnection environment106 may also have significantly more open space (compared with theembodiments shown in FIGS. 1 and 3), which may provide certain assemblybenefits, for example for making the electrical interconnections 110between the sensor chip contact pads 112 and the corresponding pincontact pads 114, while allowing for a significantly larger mounting andsupport area for the sensor chip 408 on the support portion of theheader 105. This significantly larger mounting and support area mayallow for pressure sensing applications at higher pressure ranges whilemaintaining the same overall dimensions for the sensor chip 408 and forthe overall sensor device 400.

FIG. 6 depicts a top view layout of the sensor chip 408 (for example,the sensor chip 408 as described in FIG. 5) and it differs from thepreviously described sensor chip (for example the sensor chip 108 asshown and described with respect to FIGS. 1-4) in that the sensor chipcontact pads 112 may configured near the central portion of the sensorchip 408 (compared to the sensor chip contact pads 112 of the sensorchip 108 of FIG. 2, which are located closer to the periphery of thesensor chip 108). Referring again to FIG. 5, and for this sensor device400 structure, the sensor chip contact pads 115 on the sensor chip 408are relatively aligned with the central opening in support portion ofthe header 105, which may help facilitate installing the electricalinterconnections 112 between the sensor chip contact pads 112 and thepin contact pads 114. According to an example implementation of thedisclosed technology, the sensor chip 408 as shown in FIGS. 5 and 6 maybe a pressure sensor chip having a pressure responsive diaphragm thathas a centrally located boss or thicker region. In this exampleimplementation, the sensor chip contact pads may be positioned under thethicker boss region of the sensor chip diaphragm.

FIG. 7 depicts another example sensor device 500 structure configuredfor another sensor chip 508 with a different layout as compared with theprevious examples. In this example implementation, the electricalinterconnection 110 scheme may share some similarities with the sensordevice 400 as described in FIG. 5, with the difference that the sensorchip contact pads 112 of the sensor chip 508 are offset from the centerof the sensor chip 508, and opposite the measurement environment sensingarea of the sensor chip 508.

FIG. 8 depicts a top view layout of the sensor chip 508 (for example,the sensor chip 508 as described in FIG. 7) and it differs from thepreviously described sensor chips (for example the sensor chip 108 asshown and described with respect to FIGS. 1-4 and the sensor chip 408 asshown and described with respect to FIGS. 5 and 6) in that the sensorchip contact pads 112 may be offset from the center of the sensor chip508 and laterally offset from the sensing regions(s) 502 of the sensorchip 508. For example, the sensor chip contact pads 112 may be disposedon portions of pressure sensor chip regions with high stiffness and thusnot significantly responsive to pressure. In this exampleimplementation, the influence of stress or strain on the sensor outputsignal due to wire bonding, etc., may be reduced or eliminated.

FIG. 9 depicts another example sensor device 600 structure configuredwith a protective outer diaphragm 606 for providing a sealed sensor chipenvironment 608, according to an example implementation of the disclosedtechnology. In an example implementation, the outer diaphragm 606 may bemade with a metal, for example, a metal that may be the same as thatused for the header 104, and/or compatible with sealing 122 to theheader 104 components. According to an example implementation of thedisclosed technology, the outer diaphragm 606 may include a diaphragmprotrusion 610 that may act as a pushrod and may be in contact with apressure sensing region of the sensor chip 108. In accordance with anexample implementation of the disclosed technology, the outer metaldiaphragm 606 may be configured with a thickness/stiffness that willallow pressure exerted from outside the sensor device to deflect themetal diaphragm 606 and transfer the associated movement through theprotrusion 610 and to the pressure sensing region of the sensor chip108.

The example sensor device 600 as shown in FIG. 9 has many similaritiesto the sensor device 100 as depicted in FIG. 1, with the exception ofthe outer metal diaphragm 606 (with the associated sealed sensor chipenvironment 608) and a possible configuration of the support portion ofthe header 105, which in certain example implementations, may beconfigured as a separate adapter or insert 612.

According to an example implementation of the disclosed technology, allof the metal contacts 112, 114 and electrical interconnections 110 ofthe sensor device 600 may be contained in a first sealed inertinterconnect environment 106, and all the remaining portions of thesensor chip 108 that are not contained in the first sealed inertinterconnect environment 106, may be contained in the sealed sensor chipenvironment 608.

The sensor device 600 may include many or all of the features ofpreviously discussed example implementations, such as the electricalinterconnections 110 between the sensor chip contact pads 112 and thepin contact pads 114, the feedthrough pins 116, support portions of theheader 105, etc. Furthermore, as previously discussed, the headercomponents (i.e., the header 104 and the header adapter or insert 612,and the outer metal diaphragm 606) may be joined and sealed (for examplewith a header weld 122) to provide an inert and sealed interconnectenvironment 106. In an example implementation, the header weld 122 maybe made by electron beam welding, brazing, or other appropriatejoining/sealing technique.

According to certain example implementations of the disclosedtechnology, the header weld 122 may be made at the same time, or afterthe metal feedthrough pins 116 and/or feedthrough inserts 126 areinstalled and sealed to the header 104. For example, if the feedthroughpins 116 are sealed (to the feedthrough inserts 126 and) to the header104 after the two header components 104, 612 are joined and sealedtogether, then the sealing and joining process of the feedthrough pins116 (and associated inserts 126 and electrically isolating seal 130) tothe header 104 may be preferably performed in an inert environment,resulting in a sensor device 600 structure having all metal contacts112, 114 and all electrical interconnections 110 contained in a sealed,inert interconnect environment 106.

FIG. 10 depicts another example sensor device 700 structure thatincludes a protective outer diaphragm 606 for providing a sealed sensorchip environment 608, according to an example implementation of thedisclosed technology. In this example implementation, the sensor chip408 may be utilized, and the configuration of the sensor device 700 mayinclude similarities to the previously discussed sensor device 400 andsensor chip 408 as described above with respect to FIGS. 5 and 6, butwith the added outer diaphragm 606 with the associated protrusion 610.

With reference to FIGS. 9 and 10, and in a similar manner as previouslydiscussed, the sealed interconnect environment 106 may be configured bysealing (in an inert environment) the feedthrough pins 116 (and/orassociated feedthrough inserts 126 and electrically isolating seals 130)to the header 104, by sealing 118 the sensor chip to the support portionof the header 104, and by joining and sealing 122 the bottom portion ofthe header 104 with the support portion 105 to form the internalenclosure. In an example implementation, the header weld 122 may beperformed by resistance welding, brazed, or permanently joinedmechanically and electrically by another appropriate metal joiningtechnique. In an example implementation, the outer metal diaphragm 606may be attached to the header 104 (for example, at the support portion105) and also sealed 122 under an inert environment before, at the sametime, or after the sealing to provide the sealed sensor chip environment608 and the sealed interconnect environment 106. In accordance with anexample implementation of the disclosed technology, the outer metaldiaphragm 606 component may be installed by placing it over the sensorchip 108, 408 so that the protrusion 610 touches or is in contact withthe pressure responsive diaphragm portion of the sensor chip, therebyenabling the transfer of force from the applied pressure to the sensorchip. In accordance with an example implementation of the disclosedtechnology, the outer metal diaphragm 606 may be made from Kovar,stainless steel, Inconel, nickel, tungsten, molybdenum, platinum, orfrom other high temperature metal or metal alloy, and could have aplated or deposited metal layer of gold or platinum, or other suitablemetal or metal alloy. In an example implementation, the outer metaldiaphragm 606 may be joined and sealed 122 to the header 104 (and/or tothe support portion of the header 105) in a second inert environment,preferably by electron beam welding, or by brazing, or other appropriatejoining technique, resulting in a device structure with the sensor chipcontained in the sealed sensor chip inert environment 608.

According to an example implementation of the disclosed technology,sealed interconnect environment 106 may be made and sealed in the sameinert environment as is done for the sealed sensor chip environment 608.In another example implementation, these two environments 106, 608 maybe different. In certain example implementations, these two environments106, 608 may be made/created at the same time, or independent of eachother.

FIG. 11 depicts another sensor device 800 structure having a sealedenvironment 812 and having a sensor chip 808 disposed directly on asupport portion 805 of the base of the header 104, according to anexample implementation of the disclosed technology. In this exampleimplementation a pushrod 810 may be utilized to transfer externalpressure from the outer metal diaphragm 606 (and optional protrusion610) to the pressure-sensitive portion of the sensor chip 808.

FIG. 12 shows a top-view layout and an electrical interconnection schemefor a high temperature sensor chip 808, as utilized in the sensor device800 of FIG. 11, and according to an example implementation of thedisclosed technology. Also shown in FIG. 12 is the approximate positionof the pushrod 810, the sensing regions 802, and the sensor chip contactpads 112.

With reference again to FIG. 11, the sensor device 800 may be configuredwith a protective outer metal diaphragm 606 that may be sealed 122 tothe header 104 so that all the internal metal contacts 112, all internalelectrical interconnections 110, and the entire sensor chip 808 iscontained in the same sealed inert environment 812, as opposed to thepreviously described sensor devices 600, 700 which may have three headercomponents 104, 105, 606, and two separate sealed inert environmentregions 106, 608: one containing metal contacts and electricalinterconnections, and the other containing the sensor chip.

In this example implementation, the sensor device 800 may include onlytwo components that need to be joined and sealed 122 to provide theinternal sealed environment 812: the base of the header 104 and theprotective outer metal diaphragm 606. In an example implementation, thefeedthrough pins 116 and electrically isolating seal 130 (and/or orother sealed electrical feedthrough inserts—not shown) may be similar tothose shown and described with reference to the previous figures. In anexample implementation, the protective outer metal diaphragm 606 may besimilar to the protective outer metal diaphragm 606 as discussed withrespect to FIGS. 9 and 10. However, in the sensor device 800, theelectrical interconnections 110 may be made directly from the sensorchip contact pads 112 to the feedthrough pins 116 (and/or other sealedelectrical feedthrough inserts—not shown). According to an exampleimplementation of the disclosed technology, the sensor chip 808 may befunctionally similar, and may have certain similarities to thepreviously described sensor chips 108, 408; however, the sensor chip 808and associated sensor device 800 as shown in FIGS. 11 and 12 do notrequire vias or other openings in the sensor chip substrate, as shownwith respect to FIGS. 1, 3-5, 7, 9, and 10. Certain exampleimplementations of the sensor device 800 may provide a protectiveenvironment sealed in a simpler header structure and may enable areduction in the number of components and/or processing steps requiredin the manufacturing of the sensor device 800.

In an example implementation, the pushrod 810, as shown in FIG. 11 maybe eliminated, and the protrusion 610 of the outer metal diaphragm 606may directly contact with the top portion of the sensor chip 808. Inaccordance with an example implementation of the disclosed technology,the outer metal diaphragm 606 may be installed with appropriatepre-loading contact (either via the pushrod 810, or directly on thesensor chip 808) and sealed with a header weld 122 to the base portionof the header 104, using the methods as previously discussed.

In an example implementation, the sensor chip 808 may be attached orsecured to the support portion 805 of the base of the header 104.According to an example implementation of the disclosed technology, thesensor chip 808 may be attached or secured to the support portion 805 ofthe base of the header 104 using an adhesive, by using a glass seal 118,and/or by other appropriate sealing or mounting material or techniques.Next, and in accordance with an example implementation, the electricalinterconnections 110 may be made between the sensor chip contact pads112 and the feedthrough pins 116 (and other sealed electricalfeedthroughs) by wire bonding, welding, or other appropriate techniquefor joining metal wires to contacts. In an example implementation, theelectrical interconnections 110 wires may be made of gold, aluminum,nickel, platinum, or other suitable metal or metal alloy.

In an example implementation, making the electrical interconnections 110in the sensor device 800 scheme as shown in FIG. 11 (for example, usingwire bonding) may provide significant advantages in terms of assembly,particularly since the metal contacts 112 may be readily accessible andmay allow easy access for wire bonding, welding, or other metal joiningtools, without having to negotiate any relatively narrow openings orvias in the sensor chips such as in FIG. 1.

As shown in FIGS. 11 and 12, and according to an example implementationof the disclosed technology, a pushrod 810 (or similar component) may belocated and attached to the central region of the sensor chip 808 and inalignment with the pressure responsive diaphragm. According to variousexample embodiments, the pushrod 810 may be made from glass, fromsilicon, or from other appropriate material. In certain exampleimplementations, the pushrod 810 may be attached to the sensor chipusing electrostatic or anodic bonding, bonding or sealing using glasspowders or frits, or other suitable high temperature materials. Inaccordance with an example implementation of the disclosed technology,the pushrod 810 bonded and attached to the sensor chip 808 diaphragmregion may accommodate the protrusion 610 from outer metal diaphragm606, and may acts as physical linkage (together with the protrusion 610and/or the outer metal diaphragm 606) for transmitting the forceresulting from the pressure applied to or collected by outer metaldiaphragm 606. In accordance with an example implementation of thedisclosed technology, the outer metal diaphragm 606 and the base of theheader 104 may be joined and sealed (for example, with a header weld122) in an inert environment, preferably by electron beam welding, or bybrazing, or other appropriate joining technique, resulting in a devicestructure with all internal metal contacts, all internal electricalinterconnections, and the entire sensor chip contained in a sealed inertenvironment 812.

FIG. 13 is a flow diagram of a method 900, according to an exampleimplementation of the disclosed technology. In block 902, the method 900includes sealing a sensor chip to a support portion of a header, whereinthe sensor chip comprises one or more sensor contact pads, and whereinthe header includes one or more bores extending through the header. Inblock 904, the method 900 includes attaching one or more electricalisolators to the support portion of the header. In block 906, the method900 includes disposing one or more feedthrough pin contact pads on therespective one or more electrical isolators. In block 908, the method900 includes attaching respective feedthrough pins to the one or morefeedthrough pin contact pads. In block 910, the method 900 includesattaching a first end of one or more wire bonded interconnections to therespective one or more sensor contact pads. In block 912, the method 900includes attaching a second end of the one or more wire bondedinterconnections to the respective one or more feedthrough pin contactpads. In block 914, the method 900 includes installing one or morefeedthrough pins through the respective one or more bores such that theone or more feedthrough pins are in electrical communication with therespective one or more feedthrough pin contact pads. In block 916, themethod 900 includes forming a first sealed enclosure to enclose andprotect one or more of the wire bonded interconnections, the one or moresensor contact pads, the one or more feedthrough pin contact pads, theone or more feedthrough pins, and at least the first portion of thesensor chip.

Certain example implementations may further include installing aprotective outer diaphragm in communication with the sensor chip andforming a second sealed enclosure by at least a portion of theprotective outer diaphragm and by a second portion of the sensor chip.The second sealed enclosure is configured to enclose and protect atleast the second portion of the sensor chip.

According to an example implementation of the disclosed technology, theprotective outer diaphragm can include a protrusion, and installing theprotective outer diaphragm in communication with the sensor chip caninclude disposing the protrusion so that it is in mechanicalcommunication with at least a portion of the sensor chip, such as apressure sensitive portion of the sensor chip. In this manner, pressureoutside of the sensor device may be transferred to the sensor chip bythe protective outer diaphragm.

In certain example implementations, the one or more electrical isolatorsmay be configured to prevent electrical communication between the one ormore wire bonded interconnections and the header.

Certain example implementations can include installing one or moreelectrical isolators between the one or more feedthrough pins and theheader, the one or more electrical isolators are configured to preventelectrical communication between the one or more feedthrough pins andthe header.

In accordance with an example implementation of the disclosedtechnology, one or more of the first sealed enclosure and the secondsealed enclosure may be formed in an inert environment.

According to an example implementation of the disclosed technology,installing the one or more feedthrough pins can include installing oneor more pin inserts through the header and in electrical communicationwith the respective one or more feedthrough pins, and securing the oneor more pin inserts to the header by electrically isolating seals.

In certain example implementations, the one or more pin inserts can becharacterized by a metal cylinder having an open end and a closed end.The open end extends into the first sealed enclosure and is configuredto accept a respective feedthrough pin. The closed end extends outsideof the header and is configured to at least partially seal the firstenclosure.

According to an example implementation of the disclosed technology theone or more wire bonded interconnections comprise one or more of gold,copper, aluminum, nickel, platinum, and/or a metal alloy.

As disclosed herein, the sensor device is configured for use inmeasurement environments in which the sensor device may be exposed totemperature above 400° C. In some implementations, the sensor device isconfigured for use in measurement environments in which the sensordevice may be exposed to temperature above 500° C. In someimplementations, the sensor device is configured for use in measurementenvironments in which the sensor device may be exposed to temperatureabove 600° C.

Certain example implementation of the disclosed technology may greatlyslow down interdiffusion of the various metals used in the contact pads,wire bonded interconnections, pins, and sensor chip, thus allowing thedevice to survive at higher temperatures (for example, above 600° C.)for extended periods.

Certain example implementation of the disclosed technology may utilizethe enclosure and sealing techniques and elements disclosed herein toprotect the wire bonded interconnections and other sensor devicecomponents against corrosive and/or oxidizing media.

It is important to recognize that it is impractical to describe everyconceivable combination of components or methodologies for purposes ofdescribing the claimed subject matter. However, a person having ordinaryskill in the art will recognize that many further combinations andpermutations of the subject technology are possible. Accordingly, theclaimed subject matter is intended to cover all such alterations,modifications, and variations that are within the spirit and scope ofthe claimed subject matter.

Throughout the specification and the claims, the following terms take atleast the meanings explicitly associated herein, unless the contextclearly dictates otherwise. The term “connect,” “connecting,” and“connected” mean that one function, feature, structure, orcharacteristic is directly joined to or in communication with anotherfunction, feature, structure, or characteristic. The term “couple,”“coupling,” and “coupled” mean that one function, feature, structure, orcharacteristic is directly or indirectly joined to or in communicationwith another function, feature, structure, or characteristic. Relationalterms such as “first” and “second,” and the like may be used solely todistinguish one entity or action from another entity or action withoutnecessarily requiring or implying any actual such relationship or orderbetween such entities or actions. The term “or” is intended to mean aninclusive “or.” Further, the terms “a,” “an,” and “the” are intended tomean one or more unless specified otherwise or clear from the context tobe directed to a singular form. The term “include” and its various formsare intended to mean including but not limited to. The terms“substantially,” “essentially,” “approximately,” “about” or any otherversion thereof, are defined as being close to as understood by one ofordinary skill in the art, and in one non-limiting embodiment the termis defined to be within 10%, in another embodiment within 5%, in anotherembodiment within 1% and in another embodiment within 0.5%. A device orstructure that is “configured” in a certain way is configured in atleast that way but may also be configured in ways that are not listed.

As disclosed herein, numerous specific details are set forth. However,it is to be understood that embodiments of the disclosed technology maybe practiced without these specific details. References to “oneembodiment,” “an embodiment,” “example embodiment,” “variousembodiments,” and other like terms indicate that the embodiments of thedisclosed technology so described may include a particular function,feature, structure, or characteristic, but not every embodimentnecessarily includes the particular function, feature, structure, orcharacteristic. Further, repeated use of the phrase “in one embodiment”does not necessarily refer to the same embodiment, although it may.

Although this disclosure describes specific examples, embodiments, andthe like, certain modifications and changes may be made withoutdeparting from the scope of the disclosed technology, as set forth inthe claims below. For example, although the example methods, devices andsystems, described herein are in conjunction with a pressure transduceror a sensor, the skilled artisan will readily recognize that the examplemethods, devices or systems may be used in other methods, devices orsystems and may be configured to correspond to such other examplemethods, devices or systems as needed. Further, while at least oneexample, embodiment, or the like has been presented in the detaileddescription, many variations exist. Accordingly, the specification andfigures are to be regarded in an illustrative rather than a restrictivesense, and all such modifications are intended to be included within thescope of the present disclosure. Any benefits, advantages, or solutionsto problems that are described herein with regard to specificembodiments or examples are not intended to be construed as a critical,required, or essential feature or element of any or all of the claims.

What is claimed is:
 1. A sensor device, comprising: a header; one or more feedthrough pins extending through corresponding apertures in the header; a sensor chip disposed on the header, the sensor chip comprising one or more contact pads and a pressure-sensitive portion; wire bonded interconnections electrically connecting the one or more contact pads with the respective one or more feedthrough pins; an outer cover comprising a diaphragm protrusion in mechanical communication with the pressure-sensitive portion of the sensor chip; and a sealed enclosure formed by the header and the outer cover, the sealed enclosure isolating at least the wire bonded interconnections, the one or more contact pads, and the sensor chip from an external environment.
 2. The sensor device of claim 1, wherein the diaphragm protrusion in configured in direct pre-loaded contact with the pressure-sensitive portion of the sensor chip.
 3. The sensor device of claim 1, further comprising a pushrod disposed between the diaphragm protrusion and the pressure-sensitive portion of the sensor chip.
 4. The sensor device of claim 3, wherein the pushrod comprises one or more of glass, silicon, and metal.
 5. The sensor device of claim 3, wherein the pushrod is attached to a diaphragm region of the sensor chip, wherein the pushrod accommodates the diaphragm protrusion of the outer cover, and wherein the pushrod is a physical linkage configured to transmit force to the sensor chip from pressure applied to the outer cover.
 6. The sensor device of claim 3, wherein the diaphragm protrusion in configured in direct pre-loaded contact with pushrod.
 7. The sensor device of claim 1, further comprising one or more pin inserts extending through corresponding apertures in the header and in electrical communication with the respective one or more feedthrough pins, the one or more pin inserts secured to the header by electrically isolating seals.
 8. The sensor device of claim 7, wherein the one or more pin inserts each comprise a metal cylinder having an open end and a closed end, wherein the open end extends into the sealed enclosure and is configured to accept a respective feedthrough pin, and wherein the closed end extends outside of the header and is configured to at least partially seal the sealed enclosure.
 9. The sensor device of claim 1, wherein the contact pads, the wire bonded electrical interconnections, and the sensor chip are contained in the same sealed enclosure and inert environment.
 10. The sensor device of claim 1, wherein the sealed enclosure comprises an inert environment.
 11. The sensor device of claim 1, wherein the header comprises a support portion and the sensor chip is mounted on the support portion.
 12. The sensor device of claim 11, wherein the sensor chip is mounted on the support portion by one or more of an adhesive and a glass seal.
 13. The sensor device of claim 1, wherein the wire bonded interconnections electrically connect the one or more contact pads to the respective one or more feedthrough pins without requiring vias or openings in the sensor chip.
 14. The sensor device of claim 1, wherein the sealed enclosure is formed by joining the outer cover and the header.
 15. The sensor device of claim 14, wherein the sealed enclosure is formed by joining only the outer cover and the header having sealed apertures.
 16. The sensor device of claim 1, wherein the wire bonded interconnections comprise one or more of gold (Au), copper (Cu), aluminum (Al), nickel (Ni), platinum (Pt), and a metal alloy.
 17. The sensor device of claim 1, wherein the sealed enclosure is configured to improve operation reliability of the sensor device at temperatures above 400° C.
 18. The sensor device of claim 1, wherein the outer cover comprises a metal. 